Modular fan assembly

ABSTRACT

A modular fan assembly for use in a multi-device storage enclosure. In some embodiments, the fan assembly has a rigid open frame with opposing first and second ends. A first fan is connected to the first end and a second fan is connected to the second end. The first and second fans are configured to establish a fluidic airflow through the frame. An airflow diverter positioned in an intermediate portion of the frame between the first and second ends divert at least a portion of the fluidic airflow through a first aperture of the frame to cool an active element outside the frame.

RELATED APPLICATION

This application makes a claim of domestic priority to U.S. ProvisionalPatent Application No. 61/833,647 filed Jun. 11, 2013, the contents ofwhich are hereby incorporated by reference.

SUMMARY

Various embodiments of the present disclosure are generally directed toa modular fan assembly for use in a housing, such as a housing of amulti-device storage enclosure.

In accordance with some embodiments, the fan assembly has a rigid openframe with opposing first and second ends. A first fan is connected tothe first end and a second fan is connected to the second end. The firstand second fans are configured to establish a fluidic airflow throughthe frame. An airflow diverter positioned in an intermediate portion ofthe frame between the first and second ends divert at least a portion ofthe fluidic airflow through a first aperture of the frame to cool anactive element outside the frame.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a functional representation of a networked mass storage systemto illustrate a suitable operational environment for various embodimentsof the present disclosure.

FIG. 2 is a top plan representation of a storage enclosure from FIG. 1.

FIG. 3 is a schematic diagram of a modular fan assembly constructed andoperated in accordance with various embodiments.

FIG. 4 illustrates the fan assembly from FIG. 3 in conjunction with astorage enclosure in accordance with some embodiments.

FIG. 5 is an isometric depiction of the fan assembly of FIG. 4.

FIG. 6A is a side elevational depiction of the fan assembly duringoperation.

FIG. 6B shows a bottom plan view of the fan assembly of FIG. 6A.

FIG. 7 depicts the use of multiple adjacent modular fan assemblies.

FIGS. 8A and 8B show different example configurations for a midplane ofthe storage enclosure of FIG. 7.

FIG. 9 illustrates a rail configuration used to support the fanassemblies of FIG. 7.

FIGS. 10A and 10B show details concerning a latch mechanism used tosecure and mate each of the fan assemblies.

FIGS. 11A and 11B are side elevational representations of aspring-biased sealing door used in conjunction with each fan assembly insome embodiments.

FIG. 12 is a rear view of the storage enclosure of FIG. 7 to illustrateoperation of the sealing door upon removal of a selected fan assembly.

FIG. 13 is a functional block diagram of the storage enclosure of FIG.12 in accordance with some embodiments.

FIG. 14 is a flow chart illustrating a hot-swap service replacementcycle for a failed fan assembly in accordance with some embodiments.

DETAILED DESCRIPTION

The present disclosure generally relates to directed cooling systems,such as a system for internal cooling of a housing of a multi-devicestorage enclosure of a mass storage system.

Mass storage systems often employ multiple data storage devices whichare operationally arranged to provide a relatively high data capacitymemory storage space. The devices may be grouped together into a massstorage assembly (MSA) or other module that can be removably installedinto a rack system (server cabinet).

Mass storage systems can take a variety of forms including servers,cloud storage modules, RAID (redundant array of independent discs)systems, extended memory systems (JBODs, or “just a box of drives”),etc. The storage systems can be accessed locally or over a networkincluding a local area network (LAN), a wide area network (WAN), theInternet, etc. The storage devices may be individually addressable viaIP addresses through a suitable communication protocol (e.g., Ethernet,etc.). A rack-mountable storage enclosure can include the storagedevices as well as a number of other active elements such as storagedevices, control boards, power supplies, fans, boot devices, etc.

While operable to provide highly efficient computer storage,conventional mass storage systems can be subject to a variety oflimitations, including the inability to remove and replace individualactive elements while maintaining the storage enclosure in a powered,operational condition (“hot swapping”), such as in the context of aservice operation to replace a failed component or an upgrade operationwhere new and different performance elements are installed.

Accordingly, various embodiments of the present disclosure are generallydirected to a modular fan assembly suitable for use in a housing, suchas but not necessarily limited to a housing of a multi-device storageenclosure. As explained below, some embodiments provide a storageenclosure configured with a housing adapted to be mounted within a racksystem between a cold aisle (front) and a warm aisle (rear). The housingsupports a number of active elements including multiple storage devices,power supplies, control boards, boot devices, etc.

A modular fan assembly provides cooling for the various active elements.In some embodiments, the fan assembly has a rigid open frame withopposing first and second ends. A first fan is connected to the firstend of the frame, and a second fan is connected to the second end of theframe. The first and second fans are configured to establish a fluidicairflow through the frame. An airflow diverter is positioned in anintermediate portion of the frame between the first and second ends todivert at least a portion of the fluidic airflow through a firstaperture of the frame to cool an active element outside the frame.

In further embodiments, the fan assembly is slidingly installed throughthe rear of the storage enclosure housing so that the first fan isproximate an intermediate portion of the housing and the second fan isproximate the rear of the storage enclosure housing. This allows coolingair to be drawn from the cold aisle and passed adjacent the storagedevices and into the open frame. When the storage enclosure utilizes amidplane, the fan assembly can include a connector that matingly engagesa connector supported by the midplane during installation of the fanassembly. One or more apertures can be provisioned in the midplane toallow passage of the airflow from the storage devices.

A latching mechanism with a handle and a cam arrangement can be used tosecurely engage and seat the fan assembly with the storage enclosurehousing. A spring-biased sealing door can be configured to be deflectedout of the way to an open position upon installation of the fanassembly. The sealing door can transition to a closed position to sealan aperture at the rear of the storage enclosure housing upon theremoval of the fan assembly during a service event.

In this way, cooling fans can be located near intermediate portions ofthe interior of the housing to enhance cooling efficiencies, and suchcooling fans can be quickly and easily removed and replaced viahot-swapping (e.g., without the need to power down the active elementswithin the housing).

These and other features of various embodiments will become apparentbeginning with a review of FIG. 1 which generally depicts a networkedmass storage system 100 in accordance with some embodiments. The system100 includes a storage assembly 102 coupled to a computer 104 which inturn is connected to a network 106. The computer 104 can take a varietyof forms such as a work station, a local personal computer, a server,etc. The storage assembly 102 includes a server cabinet (rack) 108 and aplurality of modular storage enclosures 110.

In some embodiments, the storage rack 108 is a 42U server cabinet with42 units (U) of storage, with each unit comprising about 1.75 inches(in) of height. The width and length dimensions of the cabinet can varybut common values may be on the order of about 24 in.×36 in. Other sizescan be used. Each storage enclosure can be a multiple of the storageunits, such as 2 U, 3 U, 5 U, etc. Fully populating the rack 108 withstorage enclosures 110 can provide several Petabytes (10¹⁵ bytes) ofstorage or more for the computer 104 and/or network applications.

An example configuration for a selected storage enclosure 110 is shownin FIG. 2. The storage enclosure 110 takes a 36/2 U configuration with36 (3×4×3) data storage devices 112 in a 2 U form factor height storageenclosure housing 114. A variety of other configurations can be usedincluding storage enclosures with a total of N drives where N=12, 16,20, 24, 30, 32, 48, etc. Other heights can be used as well, such as 3 U,4 U, 5 U, etc. While 1 U height storage enclosures are contemplated, ithas been found in some cases that a thicker enclosure housing (e.g., 2 Uor greater) provides improved structural stability and vibrationresponse.

The storage devices 112 can take a variety of forms, such as hard discdrives (HDDs), solid-state drives (SSDs), hybrid drives, etc. Eachstorage device 112 includes a controller and computer memory to providestorage of user data. In a cloud computing environment, data may bestored in the form of objects (partitions) of selected size andduplicated a number of times in different zones in different storagedevices. It is contemplated that the storage devices 112 in FIG. 2 are3.5 inch (in.) form factor HDDs with nominal length and width dimensionsof 5.75 in.×4.0 in. Other styles and form factors of storage devices canbe used, including but not limited to 2.5 in. form factor devices withnominal dimensions of 4.0 in.×2.88 in.

Retractable sleds 116 are used to secure multiple sets of the storagedevices 112. The sleds can be individually extended and retracted fromthe housing 114, as shown for a selected sled 116A which has beenpartially extended from the housing 110. The sleds 116 may include sledelectronics (not separately shown) to provide status indications andother control features during enclosure operation. While the sleds 116are shown to support the storage devices 112 in a horizontal orientation(e.g., the length and width dimensions of the storage devices areparallel to the overall length and width dimensions of the storageenclosure housing 114), the sleds 116 can alternatively support thestorage devices 112 in a vertical orientation (e.g., “on edge” so thatthe length and width dimensions of the storage devices are orthogonal tothe length and width dimensions of the storage enclosure).

A midplane 118 extends in a transverse direction across the housing 114to provide electrical interconnection paths for the various storagedevices 112 and sled electronics. The midplane may take the form of afixed multi-layer printed circuit board assembly (PCBA) with variouselectrical connectors, signal traces and vias to establish the necessaryelectrically conductive signal and power paths.

Alternatively, the midplane may take a flexible configuration in whichflex circuits (e.g., cables, etc.) are used to maintain electricalinterconnection with the storage devices and sleds. When a rigidmidplane is used, extension of a sled (e.g., sled 116A) will generallyresult in the associated storage devices on the extended sled beingpowered down and disconnected from the system. Extension of a sled usinga flexible midplane may allow the associated storage devices in theextended sled to remain powered up and operational.

Other active elements in the storage enclosure 110 of FIG. 2 includedual redundant control boards 120. The control boards 120 can take avariety of forms depending on the configuration of the storage enclosure110, such as a server, a network switch, a router, a RAID controller,etc. The multiple control boards can be used in a dual mode operation tosupport failover and failback operations, or as a master/slavearrangement so that one control board provides control operations andthe other board operates in a standby mode ready to take over operationshould a fault be detected in the main control board.

Dual redundant power supplies are represented at 122. The power supplies122 provide electrical power for the control boards 120 and other activeelements of the storage enclosure 110 such as the storage devices 112.The electrical power is supplied at suitable voltage levels (e.g., 3V,5V, 12V, etc.). Redundancy is provided such that each power supply 122is rated to supply power for the entire enclosure, should the remainingpower supply or supplies be temporarily taken off line.

The control boards 120 include one or more integrated circuit (IC)devices 124. The IC devices 124 generate significant amounts of heatduring operation, requiring the use of active cooling to maintain thedevices in a suitable temperature range. Similarly, the storage devices112 can generate significant amounts of heat during operation dependingupon system loading.

Accordingly, the storage enclosure 110 further incorporates a number ofelectrical fans. Forward located fans 126 are provisioned near themidplane 118 at an intermediate location within the storage enclosurehousing 114, and rearward located fans 128 are provisioned at the rearof the storage enclosure housing 114. The respective fans 126, 128 maybe nominally identical or may be provided with different operationalcharacteristics.

Although not separately denoted in FIG. 2, it will be understood thatvent apertures are provisioned in respective front and end facingsurfaces 130, 132 of the storage enclosure housing 114. The aperturespermit cooling airflow from the cold aisle to be drawn into the front ofthe housing 114 so as to flow adjacent the storage devices 112 andmidplane 118, through the front fans 126, adjacent the control boards120 and power supplies 122, and through the rear fans 128 out the rearof the housing to the warm aisle. The power supplies 122 may similarlyincorporate fans to direct airflow through the power supply housing.

While such an arrangement can be operable, the location of the frontfans 126 within the intermediate portion of the housing can presentchallenges from a servicing standpoint should one or more of the fansrequire replacement. As noted above, the use of the retractable sleds116 permits relatively easy access to the individual storage devices112. Similarly, the other active elements such as the control boards120, the power supplies 122 and the rear fans 128 can be easily accessedthrough the rear side 132 of the housing 114.

Due to clearance and interconnectivity constraints, however, the frontfans 126 are not easily accessible from either the front or rear sides130, 132 of the housing 114. In the event of a failure of one or more ofthe front fans 126, one service option is to remove the rear fans 128and one or both of the control boards 120 from the rear of the housing114 in order to reach in, remove and replace the failed fan(s) 126. Thisrequires the storage enclosure to be powered down for a significantamount of time and provides a risk that one or more of the activecomponents may be damaged or reinstalled improperly.

Another service option is to mount the storage enclosure 110 on a set ofrails, allowing the storage enclosure to be extended forward from thestorage cabinet 108 (see FIG. 1). A service door (such as represented at134 in FIG. 1) in the top cover of the storage enclosure housing 114 canthen be opened to provide access to the forward fans 126. This approachis also associated with a number of difficulties, including the factthat the storage enclosure will likely need to be powered down prior toextension. Depending on the size and number of storage devices withinthe enclosure, the enclosure can also be unwieldy from a weightstandpoint (some storage enclosures can weigh several hundred pounds),making such service operations difficult to carry out in a fast andefficient manner.

Accordingly, various embodiments of the present disclosure are directedto a novel modular fan assembly 140 which overcomes these and otherlimitations of the associated art. A schematic depiction of the fanassembly 140 is provided in FIG. 3 to point out various features ofinterest which will be discussed in greater detail in the ensuingdrawings. It is contemplated that multiple adjacent fan assemblies 140may be utilized in a storage enclosure such as 110 in FIG. 2.

The fan assembly 140 includes a rigid open frame 142 with a first end144 and an opposing second end 146. A first fan 148 is supportedadjacent the first end 144 of the frame and a second fan 150 issupported adjacent the second end 146 of the frame. The first and secondfans 148, 150 cooperate to generate a fluidic airflow through the framein a direction from the first end 144 and toward the second end 146.

A power connector 152 is mounted to the frame 142 and electricalconduits 154, such as in the form of power cables, etc., are routedalong the frame to supply electrical power and control signals from theconnector 152 to the respective fans 148, 150. A latch mechanism 156engages the storage enclosure housing to secure the fan assembly 140 andensure mating connection of the connector.

An airflow diverter 158 is supported by the frame 142 at a mediallocation between the first and second ends 144, 146. The airflowdiverter 158 directs at least a portion of the airflow established bythe fans away from the open frame so as to provide cooling to an activeelement located outside the frame.

FIG. 4 is a top plan view of the modular fan assembly 140 in conjunctionwith a storage enclosure 160 in accordance with some embodiments. Thestorage enclosure 160 includes a storage enclosure housing 162 whichhouses various active elements of interest. The storage enclosure 160 issized to fit within a storage cabinet (e.g., 108, FIG. 1) andaccommodate a number of data storage devices (not shown) which fitwithin a storage device zone 164. The configuration and layout of thestorage devices have been omitted for clarity of illustration, but suchcan correspond to those discussed above for the storage enclosure 110.

A midplane 166 spans the storage enclosure housing 162 in a transversedirection. The midplane 166 is characterized as a rigid midplane, butsuch is merely exemplary and is not necessarily limiting. Redundantcontrol boards 168 support high power consumption IC devices 170, andredundant power supplies 172 supply electrical power for the enclosure160.

The storage enclosure housing 162 includes opposing front and rearfacing sides 174, 176. The fan assembly 140 is configured for slidinginsertion into the housing 162 through an access aperture extendingthrough the rear side 176, as shown.

FIG. 5 provides an isometric view of the modular fan assembly 140 fromFIG. 4. The frame 142 has a rectilinear configuration with elongated topsupport rails 182, 184 and elongated bottom support rails 186, 188forming respective corners of the frame 142. The support rails extendthe length of the fan assembly 140 in a horizontal direction tomechanically connect and align the first (forward) fan 148 to the second(rear) fan 150.

Support ribs 190 extend vertically between support rails 182, 186 andsupport ribs 192 extend vertically between support rails 184, 188. Nosupport ribs are shown across the medial portions of the top or bottomextents of the frame (e.g., between rails 182, 184 and between rails186, 188) although such additional ribs can be provided as desired. Itwill be appreciated that the open frame 142 can take a number ofalternative configurations apart from that depicted in FIG. 5.

In one embodiment, at least half (50%) of the overall surface area ofthe volumetric expanse defined by the frame between the fans is open, asexemplified by FIG. 5. That is, excluding the surface areas of the firstand second ends 144, 146, the remaining surfaces (top, bottom, leftside, right side) of the volumetric expanse defined by the frame areprovided with through apertures between the interior and exterior of theframe so that a combined areal extent of the apertures is greater thanthe combined areal extent of the solid frame members (e.g., rails 182,184, 186, 188 and ribs 190, 192). Other values can be used, however,such as from about 10% to about 80% or more of the overall area of thesesurfaces being open.

It will be appreciated that closing off different sides (or portionsthereof) of the sides of the frame can enhance directional airflowthrough the enclosure, but this can also reduce the extent to which theairflow generated by the fan assembly passes outside (and back into) theframe. As used herein, an “open frame” will be understood to have atleast about 10% open sides as discussed above.

The airflow diverter 158 from FIG. 3 is shown in FIG. 5 to comprisethree adjacent, parallel airfoils 158A, 158B and 158C in spaced-apartrelation supported between the lower rails 186, 188. Each of theairfoils comprises a planar rigid material that extends at a selectedangle, such as nominally 45 degrees, with respect to the rails 186, 188.The angle of the airfoils can be any suitable acute angle with respectto the rails configured to divert at least a portion of the airflowestablished by the fans 148, 150 in the intended direction. As furthershown in FIGS. 6A and 6B, the airfoils 158A, 158B, 158C define threeadjacent apertures 194A, 194B and 194C through the bottom of the frame142. Each of the apertures is bounded by the opposing bottom rails 186,188. The first aperture 194A further extends between the fan 148 and thefirst airfoil 158A. The second aperture 194B extends between theairfoils 158A and 158B, and the third aperture extends between theairfoils 158B and 158C.

The airfoils serve to divert at least a portion of an inlet airflow,represented by arrow 196, through the apertures 194A, 194B, 194C so asto pass outside of the frame 142. As shown in FIG. 6A, the divertedairflow passes adjacent the IC devices 170 on the adjacent control board168, although other active elements can be cooled. Each of the airfoils158A, 158B and 158C are shown to have a substantially linear planarconfiguration. Other configurations are contemplated, such as but notlimited to continuously curvilinear planar configurations and segmentedlinear planar configurations with different segments extending atdifferent respective angles with respect to the rails 186, 188.

A return airflow, represented by arrows 198, passes back into theinterior of the open frame 142 through a return aperture 200 defined bythe bottom side rails 186, 188 and extending between the airfoil 158Cand the second fan 150. While it is contemplated that a large portion ofthe overall airflow established by the fan assembly 140 will thus passthrough the respective apertures 194A-194C and 200, an additionalairflow represented by arrow 202 may take another path through the frame142 to provide cooling to other portions of the enclosure. Additionalfeatures, such as a second set of airfoils, etc. can be used to furtherdirect the respective airflows generated by the fan assembly 140 toachieve desired levels of cooling based on the requirements of a givenapplication.

Referring again to FIG. 5, it can be seen that the second (rear) end 146of the frame 142 can be provided with a protective cover plate 204. Theprotective cover plate 204 includes an array of relatively smallapertures 206 through which the return flow 198 passes (see FIG. 6A).Fasteners 208 can be used to secure the cover plate 204, and as desiredthe fan 150, to the frame 142. Similar fasteners and cover plates can beused on the front facing side 144 of the frame 142 as desired.

FIG. 7 shows a total of four (4) modular fan assemblies nominallyidentical to the fan assembly 140 of FIGS. 4-6. The fan assemblies arerespectively identified as fan assemblies 140A, 140B, 140C and 140D. Fanassemblies 140A, 140B and 140D are shown in an installed orientation,and fan assembly 140C is shown in a removed orientation. For reference,the control boards 168 can be supported within removable trays 210, 212located below adjacent pairs of the fan assemblies. In this way, thefirst two fan assemblies 140A, 140B can provide primary cooling for thecontrol board 168 supported in tray 210, and the second two fanassemblies 140C, 140D can provide primary cooling for the control board168 supported in tray 212.

The rigid midplane 166 includes spaced apart electrical connectors tomatingly engage the fan assemblies. The midplane connector for the fanassembly 140C is denoted at 214. The respective connectors 152, 214 cantake any suitable configuration including pins, spring clips, traces,etc. Guide mechanisms can be used to help ensure proper alignment of therespective connectors during seating operations.

The midplane 166 is further shown to include a number of spaced apartapertures 216. The apertures extend through the midplane 166 tofacilitate airflow from the storage device zone 164 and into the fanassemblies. FIG. 8A shows the midplane 166 in greater detail (themidplane connectors 214 have been omitted for clarity of illustration).A total of 10 apertures 216 extend through medial portions of themidplane 166, although other numbers, locations and shapes of theapertures can be provided.

FIG. 8B shows an alternative rigid midplane 166A with a turretconfiguration. Apertures 218 extend between adjacent projections 220 toallow airflow to pass therethrough. The overall height of the midplanecan be adjusted to facilitate passage of airflow from the data storagedevice zone 164.

Guide rails such as depicted at 222 in FIG. 9 can be aligned to supportthe fan assemblies along the lengths thereof The guide rail 222 is shownto be disposed between fan assembly 140A and fan assembly 140B. Theguide rail 222 provides top and side guide surfaces to slidingly engageand support corresponding notches in the respective bottom support rail188 of fan assembly 140A and bottom support rail 186 of fan assembly140B. Other configurations for the guide rails used to support the fanassemblies can be used, including configurations that utilize rollers,low friction sliding plates, spring biased tracks, etc. Generally, therails are intended to provide sufficient guidance for the fan assembliesduring sliding insertion therein to ensure proper alignment andengagement with the midplane connectors (e.g., 214, FIG. 7).

Referring again to FIG. 5, the latch mechanism 156 is disposed adjacentthe second (rear) end 146 of the frame 142 to facilitate removal andinstallation of the fan assembly 140. The latch mechanism 156 includes ahinged handle member 224 that pivots about corresponding pivot shafts226 on opposing sides of the frame 142. A cam member 228 extends fromthe handle 224 at a distal end thereof.

As shown by FIGS. 10A and 10B, during insertion of the fan assembly 140the handle 244 is raised relative to frame 142 to permit sliding passageof the cam member 228 past a locking tab 230 which is supported by thestorage enclosure housing 162. The user then lowers the handle 224,bringing the cam member 228 into contacting engagement with a camsurface of the locking tab 230, which advances the fan assembly 140forward and locks the fan assembly into place.

It is contemplated that the engagement between the cam member 228 andthe tab 230 may be used to supply the requisite insertion force to fullymate the fan assembly connector 152 with the midplane connector 214 (seeFIG. 7). However, in other embodiments the electrical interconnection ofthe fan assembly 140 with the requisite power source (e.g., powersupplies 172) is carried out independently of the securement and lockingsupplied by the latch mechanism 156. For example, the user can latch thefan assembly 140 into place and then manually connect a “dangling”connector of the fan assembly to a corresponding available connectorfrom the power supplies to electrically interconnect the fans 148, 150for operation. These and other alternatives will be readily apparent tothe skilled artisan in view of the present disclosure.

To subsequently remove the fan assembly 140, the user raises the handle224 to release the cam member 228 from the locking tab 230. This allowsthe user to pull on the handle 224 to retract the fan assembly from thestorage enclosure housing.

It is contemplated that the fan assemblies 140A-140D are hot swappableso that in the event of a failure, the storage enclosure 160 can bemaintained in an operational mode while a selected one of the fanassemblies is removed and replaced. For example, with reference again toFIG. 7, the failure of fan assembly 140C can result in the removal ofthe failed unit while the remaining fan assemblies 140A, 140B and 140Dcontinue to provide cooling for the enclosure 160. One problem this maypresent is the fact that the removal of fan assembly 140C results in alarge opening at the rear of the storage enclosure housing. This openingmay produce a significant loss of internal pressure and reduction in theoperational efficiencies of the remaining fan assemblies.

FIGS. 11A and 11B depict a sealing door 232 that can temporarily closeoff the storage enclosure housing 162 upon removal of the individual fanassemblies. FIG. 11A shows the door 232 in a normally open position, andFIG. 11B shows the door 232 in a closed position.

The door 232 generally comprises a planar cover member 234 that ispivotal about a pivot shaft 236 supported by the interior of the storageenclosure housing 162. The cover member 234 is sized to substantiallycover and seal off the associated opening produced by the removal of thefan assembly.

A biasing mechanism, such as coiled spring 238, applies a relativelysmall biasing force to urge the cover member 234 to the closed position.This biasing force is overcome through contact with the frame 142 duringsliding installation of the associated fan assembly 140. FIG. 12 showsthe cover member 234 in the closed position to substantially close anaperture 240 configured to accommodate the fan assembly 140C.

FIG. 13 is a functional block representation of a storage enclosure 250to illustrate an interplay configuration between various active elementsdisposed therein. The storage enclosure 250 includes a midplane 252 toprovide electrical interconnections for the various elements within theenclosure. On a first (rear) side of the midplane 252 are one or morecontrol boards 254 which house one or more controllers 256 to providetop level control of the enclosure. A boot device 258 can be used toprovide a boot sequence during enclosure initialization. Power supplies260 supply electrical power, and a plurality of the fan assemblies 140to provide active cooling in a manner discussed above.

On an opposing second (front) side of the midplane 252 are a number ofretractable sleds 262, each supporting one or more storage devices 264and sled control electronic modules 266.

A monitoring circuit 268 may be disposed adjacent the fan assemblies 140and provides a number of monitoring functions for the enclosure, such ascontrol, status, and temperature levels during operation. In someembodiments, the monitoring circuit 268 detects the failure of aselected fan assembly 140, either via direct means throughcommunications and/or monitoring of signals associated with the fanassembly or via indirect means such as through a localized increase intemperature adjacent the fan assembly.

The monitoring circuit 268 can be configured to provide an input to thecontroller 256 which signals, such as through an external communicationlink (e.g., computer 106 in FIG. 1), the need for a service event toattending personnel. A service operation can thereafter be scheduled toreplace the failed fan assembly.

In further embodiments, the controller can operate to increase theoutput (e.g., fan speeds, etc.) of the remaining non-failed fanassemblies 140 to compensate for the temporary loss of airflowgeneration due to the failed fan assembly. For example, with referenceagain to FIG. 7, the failure of fan assembly 140C may result in anincrease in the operational rate of adjacent fan assembly 140D in orderto provide enhanced cooling for the control board 168 housed within tray212. The other fan assemblies 140A, 140B may remain unaffected, or thesefan assemblies may also be adjusted to higher rates of operation.

In some cases, an immediately adjacent fan assembly may be increased toa first level (e.g., from about 50% to about 100% total airflow (CFMoutput) rate, and other fan assemblies may be increased to a differentsecond level (e.g., from about 50% to about 70%) to compensate for thelost fan assembly. Upon the detected installation and operation of anew, replacement fan assembly, the other fan assemblies may be returnedto normal operation (e.g., 50% total airflow rate). The use of a sealingdoor such as 232 can enhance the efficiencies of the remainingoperational fan assemblies.

FIG. 14 is a flow chart for a storage enclosure operation routine 300 tosummarize the foregoing discussion. A storage enclosure such as 160, 250is configured with various active elements at step 302 such as storagedevices, power supplies, control boards and fan assemblies 140. Thestorage enclosure is thereafter operated at step 304 to write data toand read data from the storage devices in accordance with the dictatesof the operational environment.

Upon detection of an anomalous condition for a selected fan assembly 140at step 306, the selected fan assembly is powered down (as required) andthe output of the remaining fan assemblies may be increased as discussedabove, step 308.

The failed fan assembly is removed at step 310, which may include theautomatic closing of a sealing door as represented in FIG. 12. A new,replacement fan assembly is slidingly installed and locked into place atstep 312, and the new fan assembly is activated while the remainingactive fan assemblies are returned to normal operational levels at step314.

It will now be appreciated that the module fan assemblies as embodiedherein can provide a number of benefits through active directed coolingof active elements, easy replacement of fan assemblies located inintermediate portions of a housing, and efficient mechanisms to permithot swapping of failed fan assemblies without requiring the activeelements within the housing to shut down or otherwise reduce operationalloading.

The configuration and locations of the fan assemblies further enable thehot swapping of other active elements such as but not limited to storagedevices, power supplies, control boards, etc. While various embodimentshave been directed to a multi-device storage enclosure environment, itwill be appreciated that such is merely illustrative of variousembodiments and is not necessarily limiting. Rather, any number ofdifferent types of housings with active elements therein can be adaptedfor use of the modular fan assemblies as disclosed herein.

It is to be understood that even though numerous characteristics ofvarious embodiments of the present disclosure have been set forth in theforegoing description, together with details of the structure andfunction of various embodiments, this detailed description isillustrative only, and changes may be made in detail, especially inmatters of structure and arrangements of parts within the principles ofthe present disclosure to the full extent indicated by the broad generalmeaning of the terms in which the appended claims are expressed. Forexample, the particular elements may vary depending on the particularapplication without departing from the spirit and scope of the presentdisclosure.

What is claimed is:
 1. An apparatus comprising: a rigid open framehaving opposing first and second ends; a first fan connected to thefirst end; a second fan connected to the second end, the first andsecond fans configured to establish a fluidic airflow through the frame;and an airflow diverter positioned in an intermediate portion of theframe between the first and second ends to divert at least a portion ofthe fluidic airflow through a first aperture of the frame to cool anactive element outside the frame.
 2. The apparatus of claim 1, whereinthe first and second fans each have a rectangular cross-sectional areanominally corresponding to an interior cross-sectional area of the framein a length direction from the first end to the second end.
 3. Theapparatus of claim 1, further comprising an electrical connectorconnected to the frame and configured to engage a correspondingelectrical connector on a midplane of a storage enclosure to supplyelectrical power to the first and second fans.
 4. The apparatus of claim1, further comprising a latching mechanism coupled to the frame whichengages a housing of the storage enclosure to seat and lock the frame tothe housing.
 5. The apparatus of claim 1, wherein the airflow divertercomprises at least one airfoil which extends across at least a portionof an internal cross-sectional area of the frame to divert the portionof the fluidic airflow through the first aperture.
 6. The apparatus ofclaim 5, wherein the frame further comprises a second aperture betweenthe first aperture and the second fan to admit the portion of thefluidic airflow back into an interior of the frame for exhausting by thesecond fan.
 7. The apparatus of claim 1, wherein the airflow divertercomprises a plurality of spaced-apart parallel airfoils which extendinto an interior of the frame to divert the portion of the airflow fromthe first fan, the airfoils extending at an acute angle with respect toa base surface of the frame through which the first aperture extends todivert said airflow.
 8. The apparatus of claim 1, further comprising aplurality of storage devices on a first side of a midplane and a controlboard on an opposing second side of the midplane, the midplane having aplurality of electrical interconnections to interconnect the storagedevices to the control board, wherein the frame and the first and secondfans are on the second side of the midplane to direct the fluidicairflow from the storage devices through the midplane.
 9. The apparatusof claim 8, wherein the portion of the fluidic airflow is diverted bythe airflow diverter to pass adjacent the control board.
 10. Theapparatus of claim 1, wherein the frame comprises a plurality of spacedapart support rails which adjoin and extend between the first and secondfans and at least one support rib which extends from a first supportrail to a second support rail, wherein open apertures are formed betweenadjacent pairs of the support rails and adjacent opposing sides of thesupport ribs.
 11. The apparatus of claim 10, wherein the airflowdiverter comprises a plurality of parallel, spaced apart airfoils eachairfoil supported between an adjacent pair of the support rails andextending at a selected skew angle with respect to the support rails.12. The apparatus of claim 10, wherein a total combined surface area ofthe open apertures along respective sides of the frame constitute atleast 50% of a total combined surface area of the areal extent of therespective sides.
 13. An apparatus comprising: a storage enclosurehousing having opposing front and rear ends, the front end adapted forplacement adjacent a cold aisle zone and the rear end adapted forplacement adjacent a warm aisle zone; a plurality of data storagedevices disposed within the storage enclosure housing adjacent the frontend thereof; and a plurality of fan assemblies disposed within thestorage enclosure housing between the data storage devices and the rearend, each of the fan assemblies comprising a rigid open frame having aproximal end and a distal end, a first fan connected to the proximalend, a second fan connected to the distal end, the first and second fansconfigured to establish a fluidic airflow through the frame, and anairflow diverter positioned in an intermediate portion of the framebetween the proximal and distal ends to divert at least a portion of thefluidic airflow through a first aperture of the frame to cool an activeelement adjacent the frame.
 14. The apparatus of claim 13, furthercomprising a control board and a midplane disposed between the datastorage devices and the fan assemblies to establish electricalinterconnections between the data storage devices and the control board,wherein the fluidic airflow passes from the data storage devices,adjacent the midplane and through the frame.
 15. The apparatus of claim14, wherein the portion of the fluidic airflow diverted by the airflowdiverter is directed across the control board for cooling thereof. 16.The apparatus of claim 13, further comprising at least one electricalpower supply disposed within the storage enclosure housing adjacent theplurality of fan assemblies to supply electrical power to the datastorage devices and to the first and second fans of each of the fanassemblies.
 17. The apparatus of claim 13, wherein each of the fanassemblies further comprises a latching mechanism which uses a cam tosecure the associated fan assembly within the storage enclosure housing.18. The apparatus of claim 13, wherein the housing has an associatedaperture to accommodate sliding insertion from the rear end thereof ofeach of the plurality of fan assemblies, and wherein the apparatusfurther comprises a corresponding plurality of sealing doors configuredto nominally cover the associated aperture responsive to sliding removalof the associated fan assembly from the storage enclosure housing. 19.The apparatus of claim 13, further comprising a plurality of railsadapted to slidingly engage the plurality of fan assemblies duringsliding insertion thereof into the data storage housing.
 20. Theapparatus of claim 13, further comprising a control circuit which,responsive to a detected anomalous condition associated with a first fanassembly of said plurality, increases an operational rate of the firstand second fans in a second fan assembly of said plurality adjacent thefirst fan assembly to compensate for loss of operation of the first fanassembly.